Abstract
Most endophytes isolated from plants and algae are members of the Ascomycota or their anamorphs, with only a few reports of basidiomycetous endophytes, these often being orchid mycorrhizas. Fungal endophyets were isolated from healthy leaves, rachis and petioles of the oil palm Elaeis guineensis in a Thai plantation. In two experiments 892 and 917 endophytes were isolated yielding 162 and 178 morphotypes, respectively. Non-sporulating isolates were grouped into 162 morphotypes according to their colony morphology. Many of these morphotypes were shown to be basidiomycetes as clamp connections were present and some produced basidia and basidiospores in Culture. Thirteen basidiomycetous morphotypes were therefore further characterized by molecular analysis using ribosomal DNA Sequences. The LSU region was used to clarify the ordinal taxonomic level status of these isolates. The phylogenetic position of the basidiomycetous endophytes was separated into two major lineages, two and eleven in the Agaricales and Polyporales, respectively. Based oil ITS sequence analysis the two Agaricales strains grouped with Schizophyllum species and showed a close relationship with S. commune. Within the Polyporales two and nine strains had an affinity with the Polyporaceae and Fomitopsidacae, respectively. One of the endophytic Polyporaceae strains was monophyletic with seven sequences of Pycnoporus sanguineus, while another isolate grouped with a fungal endophyte DQ979682 and Trametes elegans. The largest fungal assemblage was within the Fomitopsidaceae, four endophytic isolates clustered with Fomitopsis species (F. ostreiformis, F. palustris), two and three isolates grouped with Fomitopsis pinicola and Fomitopsis meliae, respectively. Numerous genera of the Basidiomycota are reported herein as endophytes and are the first report of basidiomycetous endophytes from oil palm. Our analysis demonstrated that LSU and ITS data,ire powerful tools to resolve the taxonomy of basidiomycetous endophytes. The biological role of these endophytes is discussed.